Metal beverage container with improved finish geometry

ABSTRACT

A metal beverage container may include a body portion, a neck portion connected with said body portion, and a finish portion. The finish portion may include a threaded portion, a lip portion, and a transition portion coupled between the threaded portion and the lip portion. The transition portion may include an outwardly convex shape.

RELATED APPLICATIONS

This application claims priority to co-pending U.S. Provisional Application Ser. No. 61/600,074 filed Feb. 17, 2012, the contents of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

This disclosure relates to metal beverage containers, and more particularly, but not by way of limitation, to finish portions of metal beverage containers.

BACKGROUND

A bottle shaped metal beverage container may include an opening at one end sealed by a closure element, such as a cap. A bottle cap is typically installed by machinery and, in certain examples, twisted or pressed onto the beverage container. This twisting or pressing operation generally causes a certain amount of force for the cap to be properly seated. This force may result in axial loading of the beverage container and damage to the beverage container. To reduce material and transportation costs, beverage containers having configurations that reduce material consumption and weight while retaining the ability to withstand applied loads are desirable.

SUMMARY

To minimize or prevent damaging a beverage container due to axial forces, compressive forces, and other forces being applied during a capping process, for example, the following disclosure provides for incorporating an arc structure that is outwardly convex below a lip area of the beverage container. The arc may be shaped based on a wall thickness of the beverage container, material of the beverage container, amount of force or load to be applied, and possibly other factors. The shape of the arc may vary in radius, the radius setting an angle at a transition section below the lip at the top of the beverage container, if shaped as a bottle.

More particularly, a finish portion of a metal beverage container includes a lip portion and a threaded portion. The finish portion also includes a transition section. The transition section may include an outwardly convex portion connecting the lip and threaded portions. The lip portion may define a sealing surface that seals against a closure element. The threaded portion may engage threads of the closure element. The outwardly convex portion may have a thickness between approximately 0.125 millimeters and approximately 0.75 millimeters. The outwardly convex portion may have a radius of curvature between approximately 1.0 millimeter and approximately 6.0 millimeters. The outwardly convex portion may have an arc length between approximately 1.0 millimeter and approximately 5.0 millimeters. The transition section may comprise aluminum, steel, or alloys thereof. The outwardly convex portion may be shaped such that the transition section can bear an axial load between approximately 100 Newtons and approximately 3000 Newtons, depending on the style and configuration of beverage container and manufacturing process, without plastically deforming. Other dimensions of the thickness, radius of curvature, and arc length are also contemplated and may vary depending on the materials, manufacturing process, or otherwise.

A metal beverage container includes a body portion, a neck portion connected with the body portion, and a finish portion connected with the neck portion. The finish portion includes a lip portion defining a sealing surface that seals against a closure element (e.g., cap), a transition section, and a threaded portion that engages threads of the closure element. The transition section may include an outwardly convex portion connecting the lip and threaded portions. The finish portion may comprise aluminum, steel, or alloys thereof. The finish portion may have a maximum diameter between 20 millimeters and 42 millimeters. The outwardly convex portion may be shaped such that the transition section can bear, for example, an axial compressive load between approximately 800 Newtons and approximately 1000 Newtons without plastically deforming. Higher loads are also possible since container top load specifications of beverage containers may be 350 lbs or approximately 1560 Newtons or higher. The shape of the outwardly convex portion may also provide a certain compliance or elastic deformation to absorb a certain level of axial forces and other forces. In this manner, the convex portion may resist permanent plastic deformation and yielding, and may allow for wider manufacturing tolerances. Other axial loads that are higher or lower are also contemplated.

One embodiment of a metal beverage container may include a body portion, a neck portion connected with said body portion, and a finish portion. The finish portion may include a threaded portion, a lip portion, and a transition portion coupled between the threaded portion and the lip portion. The transition portion may include an outwardly convex shape.

One method of manufacturing a metal beverage container may include forming a body portion, forming a neck portion connected with the body portion, and forming a finish portion connected with the neck portion. The finish portion may be formed by forming a threaded portion, forming a lip portion, and forming a transition portion coupled between the threaded portion and the lip portion. The transition portion may include an outwardly convex shape.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view illustration of an illustrative embodiment of a metal beverage container;

FIGS. 2-5 are side view illustrations, in cross-section, of illustrative embodiments of top portions of metal beverage containers; and

FIG. 6 is a flow diagram of an illustrative embodiment of a process of manufacturing a metal beverage container in accordance with the principles of the present invention.

DETAILED DESCRIPTION

Axial loading of a bottle shaped metal beverage container may cause the beverage container to deform. Certain deformations (e.g., plastic or permanent deformations) may be undesirable. A metal beverage container, however, may be designed to withstand certain amounts of axial loading. For example, a thickness of the metal used to form the beverage container may affect the container's ability to bear axial load (e.g., the thicker the metal for a given container design, the greater the ability of the container to withstand axial loads, generally speaking).

Metal is often purchased by weight. A thicker beverage container may be associated with increased material and transportation costs. Hence, relatively thin (and/or light weight) metal beverage containers capable of withstanding axial loads sufficient to properly seat a closure element (e.g., bottle cap, either twist or pop-off) may be desirable.

Referring to FIG. 1, a metal beverage container 100 may include a body portion 102, a neck portion 104 and a finish portion 106, as commonly referred to in the art. The finish portion 106 includes an opening (not shown) that may be used to access an interior of, the beverage container 100 and may receive a closure element 108 with threads 110 to seal the beverage container 100. A center line to the beverage container 100 is also illustrated. Capping operations may result in loading of the beverage container 110 in the general direction of this centerline.

By way of example, but not by limitation, the overall height of the beverage container 100 may be approximately 185 millimeters, the overall height of the finish portion 106 may be approximately 20 millimeters, the outside diameter of the beverage container 100 at its widest may be approximately 53 millimeters, and the outside diameter of the finish portion 106 at its widest may be in the range of 20 to 42 millimeters. Of course, other dimensions and/or shapes are also contemplated.

The metal from which the beverage container 100 is formed, in the example of FIG. 1, is aluminum. Other suitable metals, such as steel and certain alloys (e.g., aluminum-steel alloys, etc.), however, may also be used. In one embodiment, a 3000 series aluminum may be utilized. In particular, a 3104 series aluminum may be utilized. The aluminum may be annealed or unannealed. The thickness of the metal may vary among the body portion 102, neck portion 104, and finish portion 106, or within any of the portions 102, 104, and 106. As an example, the average thickness of the neck portion 104 may be approximately 0.23 millimeters and the average thickness of the finish portion 106 may be approximately 0.33 millimeters. The thickness of the neck portion 104 adjacent to the body portion 102 may be 0.20 millimeters, and the thickness of the neck portion 104 adjacent to the finish portion 106 may be approximately 0.28 millimeters, etc. These thicknesses are illustrative and alternative thicknesses may be utilized.

Referring to FIG. 2, the finish portion 106 of the metal beverage container 100 of FIG. 1 includes a lip portion 202, a threaded portion 204, a transition section 206 connecting the lip portion 202 and threaded portion 204, a tamper evidence bead 208, and a tamper evidence band receiving portion 210. The lip portion 202, in this example, includes a curl defining a sealing surface 212 for a closure element. The threaded portion 204 includes threads 214 on which corresponding threads of the closure element may be received. The tamper evidence bead 208 receives a tamper evidence band during closure element application. The tamper evidence band rests on the tamper evidence band receiving portion 218 after it has been separated from the closure element, as understood in the art.

A line 216 is shown passing through the transition section 206 connecting the lip portion 202 and threaded portion 204. As apparent from the figure, the transition section 206 is aligned with the line 216. Put another way, the transition section 206 is straight.

It has been discovered that axial loads applied during capping operations may cause deformation of the finish portion 106. For example, a hinge point 218 may form at the interface between the transition section 206 and the threaded portion 204. The transition section 206 is shown to be at an angle θ from horizontal. A length SL between the hinge point 218 and centerline 220 of the sealing surface 212 (curl) may range from approximately 3.3 mm and 6.1 mm. The higher the length SL, the axially stronger the transition section 206 as a result of being more vertical. Stresses associated with axial loads may concentrate at this hinge point 218, thereby causing deformation in the vicinity of the hinge point 218 as well the threads 214. This deformation may result in (i) an improper seal between the finish portion 106 and the cap and/or (ii) increased opening torque. In addition, inclusion of an arc in the transition section 206 helps to account and adjust for variations in manufacturing of the lip portion 202 as variations (e.g., non-uniformity) in height and/or shape of the lip portion 202 may cause different axial compressive forces to be applied to different portions of the lip portion 202 and, consequently, the transition section 206. The finish portion 106 and the hinge point 218, or transition sections, as explained above, may be thickened to reduce the tendency to deform under axial loads. Thickening these transition sections, however, may result in heavier and, thus, more costly beverage containers.

It has also been discovered that modifying the geometry of transition sections such that they have a convex shape or radially outward profile (see FIGS. 3-5) improves their ability to distribute and withstand axial loads without plastically (or permanently) deforming. Hence, a finish portion of a given thickness and having a convexly shaped transition section may exhibit a reduced tendency to plastically deform under a given axial load compared with a finish portion of the same thickness and having a straight or concavely shaped transition section. Likewise, a thinner convexly shaped transition section may exhibit the same performance under a given axial load as a thicker straight or concavely shaped transition section.

Simulation has revealed that, for a given metal thickness, a convexly shaped transition section may result in improved resistance to permanent deformation relative to a straight or concavely shaped transition section. One reason for such an improvement is that the substantial linearity of a straight transition section provides for a linear spring response, whereas the convexly shaped (FIG. 3) or compound curve shaped (FIGS. 4 and 5) transition section provides for a non-linear response to a load applied to the transition section as a result of having a non-linear shape. If, for example, axial loads of 800 Newtons associated with a filling or capping operation were routinely used on containers having a straight or concavely shaped transition section, the same or higher axial loads associated with a filling or capping operation may be routinely used on containers having a convexly shaped transition section (given the same metal thickness) since the convexly shaped transition section may be compliant to offset some of the load. The inclusion of an outwardly convex or compound transition section may allow for an increase in loads used to form threads in an applied closure, which may make thread formation more repeatable during such operations. It should be understood that alternative transition section designs may provide for higher, and possibly significantly higher, axial strength in accordance with the principles of the present invention.

Convexly shaped transition sections may be particularly suitable for finish portions having diameters in the range of 26 millimeters to 40 millimeters, for example. Such convex shapes, however, may be used with finish portions of any suitable diameter.

Referring to FIG. 3, an illustrative finish portion 300 of a container includes a lip portion 302, a threaded portion 304, a transition section 306 connecting the lip portion 302 and threaded portion 304, a tamper evidence bead 308, and a tamper evidence band receiving portion 310. The lip portion 302, in this example, includes a curl defining a sealing surface 312 adapted to seal against a closure element, such as the closure element 108 of FIG. 1. The threaded portion 304 includes threads 314 on which corresponding threads of, for example, the closure element 108 may be received. The tamper evidence bead 308 receives a tamper evidence band (not shown) during closure element application. The tamper evidence band rests on the tamper evidence band receiving portion 310 after it has been separated from the closure element.

A straight line 316 is shown relative to the transition section 306 connecting the lip portion 302 and the threaded portion 304. As apparent from FIG. 3, the transition section 306 has a convex shape or radially outward profile. That is, the transition section 306 bulges outward away from the interior of the container. As a result, the angle θ of the transition section 306 may be higher than that of the straight transition section 206 of FIG. 2. Moreover, because the transition section 306 includes an arc, the transition section 306 is longer than a transition section that is a straight line, such as transition section 206 of FIG. 2.

Referring to FIG. 4, another illustrative finish portion 400 includes a lip portion 402, a threaded portion 404, a transition section 406 connecting the lip portion 402 and threaded portion 404, and a tamper evidence bead 408. The lip portion 402 may include a curl defining a sealing surface 410. The threaded portion 404 includes threads 412. In the example of FIG. 4, the tamper evidence bead 408 may have a diameter in the range of 20 to 42 millimeters. Other diameters, however, are also contemplated.

A straight line 414 is shown relative to the transition section 406 and connects the lip portion 402 and threaded portion 404. As shown, the transition section 406 has a convex shape or radially outward profile. In the example of FIG. 4, the transition section may have a thickness in the range of approximately 0.125 to approximately 0.75 millimeters, a radius of curvature in the range of approximately 1.0 to approximately 6.0 millimeters, and an arc length in the range of approximately 1.0 millimeter to approximately 5.0 millimeters. Other thicknesses, radii or curvature, and arc lengths, however, are also contemplated.

Referring to FIG. 5, yet another illustrative finish portion 500 includes a lip portion 502, a threaded portion 504, and a transition section 506 connecting the lip portion 502 and threaded portion 504. The lip portion 502 includes a curl defining a sealing surface 508. The threaded portion 504 includes threads 510.

A straight line 512 is shown relative to the transition section 506 connecting the lip portion 502 and threaded portion 504. As shown, the transition section 506 has a convex shape or radially outward profile. Furthermore, the compound transition section may have a portion that extends away from and toward the interior of the beverage container.

As can be seen between each of FIGS. 3, 4, and 5, the radius defined by the transition sections 306, 406, and 506 may vary. By varying the radius of the transition section 306, an angle at which the transition section 306 meets both the threaded portion 304 and lip portion 302 varies. The more vertical the transition section 306, the more axial strength. As shown, FIG. 5 shows the most vertical transition portion 506 as exemplified by the line 512, while the transition sections 406 and 306 are more horizontal, respectively, as further exemplified by the lines 414 and 316. The angle of the transition portion 506 may range from approximately 10 degrees to approximately 45 degrees from vertical (or from approximately 45 degrees to approximately 80 degrees from horizontal). When establishing the radius of the transition section 306, factors including shape, stiffness, length, applied force, compliance, and so forth may be considered. As such, the radius and length of the transition section 306 along with the thickness and material of the finish portion 300, curl shape and configuration of the lip portion 302, and other aspects of the finish portion 300 may be optimized for the overall configuration of the metal beverage container, closure element, lip displacement, and manufacturing processes.

As an example of optimizing the finish portion, a number of design options are presented below in TABLE I, which varies arc radius of the transition section and finish thickness.

TABLE I Optimization of Design Parameters Design Arc Finish Peak Force Option Radius Thickness and Displacement 1 1 mm 0.125 mm 146.8 N @ 0.37 mm 2 6 mm 0.125 mm 189.8 N @ 0.53 mm 3 straight 0.125 mm 205.6 N @ 0.61 mm 4 1 mm 0.500 mm   196 N @ 0.43 mm 5 6 mm 0.500 mm  2133 N @ 0.44 mm 6 straight 0.500 mm  2200 N @ 0.55 mm

As shown in these results, the larger the radius of the arc of the transition section 306, the higher the peak force and displacement. This is, in part, as a result of the transition section 306 being more vertical. Similarly, the thicker the finish thickness, the higher the peak force capabilities, where the peak force and displacement indicates a force and displacement at which the transition section 306 fails or permanently deforms. While a finite element analysis shows that a transition that is straight has a peak force and displacement that is higher than a transition section with an arc configured with a radius, use of a straight transition portion may make the transition portion susceptible to plastic deformation given that stresses are concentrated at a hinge point, as described in FIG. 2, and especially true as the finish thickness of the transition portion is decreased to reduce weight and cost of the metal beverage container. That is, by the transition portion having at least some arc being outwardly convex, the transition portion balances strength and compliance or elasticity to provide a metal beverage container that is less susceptible to complications that may arise from manufacturing defects when capped.

With regard to FIG. 6, a flow diagram of an illustrative embodiment of a process 60 of manufacturing a metal beverage container in accordance with the principles of the present invention is shown. The process 600 may start at step 602, where a body portion of the metal beverage container may be formed. The body portion may be shaped as a bottle. At step 604, a neck portion of the metal beverage container may be formed. In forming the neck portion, the neck portion may be formed using the same material as the body portion. The neck and body portion may be formed on a single piece of material or separate pieces and connected to one another. At step 606, a finish portion may be formed. In forming the finish portion, the finish portion may be the same material or separate material from the neck and body portions. The finish portion may connected to the neck portion if formed on a separate material. The material of the three portions may have the same or different composition. In forming the finish portion, the finish portion may included a threaded portion, lip portion, and transition portion including an outwardly convex shape coupled between the threaded portion and the lip portion. In one embodiment, the transition portion may be a compound shape, where a convex and concave or “s” shaped curve is utilized. Thickness of the material, shape of the transition portion, and other parameters of the transition portion may be of those provided herein.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.

Furthermore, the figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the principles of the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, may be desired for particular applications or implementations.

The previous detailed description is of a small number of embodiments for implementing the invention, and is not intended to be limiting in scope. One of skill in the art may envisage methods and variations used to implement the principles of the invention in other areas than those described in detail herein. 

We claim:
 1. A metal beverage container, comprising: a body portion; a neck portion connected with said body portion; and a finish portion including: a threaded portion; a lip portion; and a transition portion coupled between said threaded portion and said lip portion, said transition portion including an outwardly convex shape.
 2. The metal beverage container according to claim 1, wherein said body portion, neck portion, and finish portion includes aluminum.
 3. The metal beverage container according to claim 2, wherein the aluminum is 3000 series aluminum.
 4. The metal beverage container according to claim 1, wherein the outwardly convex shape has a radius between approximately 1 mm and approximately 6 mm.
 5. The metal beverage container according to claim 4, wherein said finish portion has a thickness between approximately 0.125 mm and approximately 0.600 mm.
 6. The metal beverage container of claim 4, wherein said finish portion has a thickness of approximately 0.33 mm.
 7. The metal beverage container according to claim 1, wherein said transition portion has a length that is longer than a finish portion with a straight line.
 8. The metal beverage container according to claim 1, wherein said transition portion is configured to support an axial load between approximately 1250N and approximately 1750N.
 9. The metal beverage container according to claim 1, wherein said lip portion has a substantially circular shape.
 10. The metal beverage container according to claim 1, wherein said transition portion has an angle between approximately 45 degrees and approximately 80 degrees from horizontal.
 11. The metal beverage container according to claim 1, wherein said transition portion is a compound curve.
 12. The metal beverage container according to claim 1, wherein said transition portion has a non-linear response to a load as a result of having a non-linear shape.
 13. A method of manufacturing a metal beverage container, said method comprising: forming a body portion; forming a neck portion connected with the body portion; and forming a finish portion connected with the neck portion, the finish portion being formed by: forming a threaded portion; forming a lip portion; and forming a transition portion coupled between the threaded portion and the lip portion, the transition portion including an outwardly convex shape.
 14. The method according to claim 13, wherein forming the body, neck, and finish portions includes forming the body, neck, and finish portions of aluminum.
 15. The method according to claim 14, wherein forming the body, neck, and finish portions of aluminum includes forming the body, neck, and finish portions using 3000 series aluminum.
 16. The method according to claim 15, wherein forming the transition portion includes forming the transition with the outwardly convex shape having a radius between approximately 1 mm and approximately 6 mm.
 17. The method according to claim 16, wherein forming the finish portion includes forming the finish portion having a thickness between approximately 0.125 mm and approximately 0.600 mm.
 18. The method according to claim 16, wherein forming the finish portion includes forming the finish portion having a thickness of approximately 0.33 mm.
 19. The method according to claim 13, wherein forming the transition portion includes forming the transition portion having a length longer than a finish portion that is a straight line.
 20. The method according to claim 13, wherein forming the transition portion includes forming the transition portion with a configuration to support an axial load between approximately 1250N and 1750N.
 21. The method according to claim 13, wherein forming the lip portion includes forming the lip portion with a substantially circular shape.
 22. The method according to claim 13, wherein forming the transition portion includes forming the transition portion with an angle between approximately 45 degrees and approximately 80 degrees from horizontal. 